Success with LED and SPS

[mrhasan]

Awesome infos Thank you so much Learnt lots of new stuffs

Originally Posted by ScubaSteve

Errr... That's not necessarily true. When you see a red shirt, for example, you are seeing red because the shirt is reflecting primarily red wavelengths while absorbing most of the other wavelengths. So, if you were to shine a light on that shirt that was missing red in the spectrum, the shirt would basically look black/brown. No amount of cyan is gonna make that shirt look red. And this is where a lot of misconception comes into the whole LED schmozzle...

Corals have two different types of proteins that give rise to colors: chromophores and fluorescent proteins. Chromophores behave like the red shirt in the example above: they absorb certain wavelengths while reflecting others. You can accentuate these colours by hitting them with the colour that they are. Purple is a prime example of a colour coming from a chromophore. Often you see chromophores in growth tips of SPS there the tip is a different colour than the rest of the coral. Chromophores are Antioxidants and act like sunscreen for the relatively new flesh of the coral, which matures over time to contain more...

Fluorescent proteins. There are three main types of fluorescent protein: green (GFP), cyan (CFP) and red (rFP). These proteins behave different than the chromophores because rather than reflecting a particular wavelength, the emit a particular wavelength after being excited by a more energetic wavelength. So, for a red coral (whose colour comes from rFP and not from a chromophore), red light does dick all to enhance the red coloration. But, as you notice, when you hit that coral with a higher wavelength, like in the cyan region, the coral goes all psychedelic on you because the rFP is fluorescing (which is what gives corals that "pop"). This is why TV, RB and cyan bring back a lot of the "pop" that goes "missing" when people swap to LEDs.

Even within the GFP, CFP and rFP clades (ie. similar proteins), there are a number of proteins which all have different absorption and emission peaks. This means, for example, each rFP has a different peak excitation wavelength and different emission wavelength. Metal halides are a continuum of wavelengths, so we get that spread that covers all of the different excitation peaks and we see a balance of coral colors (though you may also notice a lot of people with halides still use T5 or LED lighting to supplement the MH and bring out other colors the MH miss).

LEDs, on the other hand, have more discrete emission peaks which, if you only use one or two types of LEDs, leaves big gaps in the combined spectrum. This in turn leads to certain colors, be it a chromophore or fluorescent protein, not being rendered. Yes, by moving towards a full spectrum you start to fill in those holes, but you still don't have the same spread that a MH does, so some corals look WOW! And some look BLAH!.

Then there is also perceived colour temperature. With just CW or NW, the tank has a yellow hew. By adding RB the tank looks more like the 14K halides we are used to but still has a bit of a sterile feel to it. By adding reds into the mix you start to add a bit of warmth into the colour (and really it doesn't take much red to do this). The addition of red doesn't actually positively effect the colour of many corals (rFP isnt excited by it and there are few orange to red chromophores). It's the mix of colours that effects more how your rocks and sand look to you, which actually plays a big part in how the tank looks to you. For example, if you used all TV and RB, everything would fluoresce like mad but to you the tank looks like blue soup because your rocks and sand look blue. But if we kept the same coloration in the coral but change the sand to white, the tank has a totally different feel to it (and would look awesome).

So, to really have a good full spectrum LED set up (or any lighting set up for that matter) you need to understand where the colour of your corals are originating from and pick your light source to accentuate the different colors of your corals. The colors of our corals originate from different processes, so we have to take this into account with the design. And there are also the colors that we need to see to balance everything out.

This isn't even getting into the whole photosynthesis argument. I'm not going to touch that one but I'll just leave it with: find a colour mix that works for you and get lots of LEDs



See above.



You don't need to have an LED for every chunk of the spectrum to do a proper full spectrum (in fact look at the spectrum of some halides and you'll see that they can totally drop out at some wavelengths and are super heavy in other areas). And because LEDs do have a distribution in wavelengths (some tighter than others), some of the tails over lap and add up. Also, you don't really need to cover all the spectrum in the UV/violet/blue range since much of these wavelength contribute to fluorescing colors while being mostly invisible to our eyes. So long as you have some wavelengths shorter than the RB, you're pretty covered as the photons less than 450 nm are energetic enough to make most colors fluoresce.

So, you can build a fairly nice, continuous spectrum with a limited number of LEDs. We certainly need more than the RB/white mixes of old but we don't need to go overboard either.

[daplatapus]

Nice info, scubasteve. Not sure I understood all of it yet, lol, but certainly made some good points and provided food for thought.

[Madreefer]

Originally Posted by daplatapus

Nice info, scubasteve. Not sure I understood all of it yet, lol, but certainly made some good points and provided food for thought.

Yea thanks Scubasteve

[ScubaSteve]

Originally Posted by daplatapus

Nice info, scubasteve. Not sure I understood all of it yet, lol, but certainly made some good points and provided food for thought.

I tried to make it as non-sciency as I could so I might have either still made it too techy or missed out some important concepts. So, if you need a clarification on anything, ask away.

[kien]

The question of UV is an interesting one. I know that for DE Halide bulbs you HAVE to use them with UV shielded glass. Well, at least I have never come across a DE halide bulb that did not require a UV shield. Also, the outer glass envelope of the mogul halide lamps are UV shielded.

[mike31154]

I did a little more digging re the UV issue & found this article. They've carried out some measurements on various bulb types, technologies, their UV output & how much UV-A in particular actually makes it through some of the so called glass shields that envelop lamps. UV-B & -C are downright nasty & can really hurt you as well as most any living thing.

http://www.aquarium-design.com/reef/uvlighting.html

[Madreefer]

So next question. Are the lenses on LEDs equipped with "uv LEDs" have the proper lenses? Same question goes out to the DIY guys. Local guy here in town decided to take the glass out of a fixture to try to get a little more use out of the MH bulbs. Bad idea. All corals fried. So with uv LEDs and not having the proper glass/lens will it be the same result? I would think so

[ScubaSteve]

Originally Posted by Madreefer

So next question. Are the lenses on LEDs equipped with "uv LEDs" have the proper lenses? Same question goes out to the DIY guys. Local guy here in town decided to take the glass out of a fixture to try to get a little more use out of the MH bulbs. Bad idea. All corals fried. So with uv LEDs and not having the proper glass/lens will it be the same result? I would think so

In LED fixtures, "UV LEDs" aren't actually UV, and if they are , they're just in the UV zone. I am using UV LEDs in my PhD work, so I can tell you with confidence that a "UV LED" and a real UV LED are two VERY different beasts. Most of the LEDs used in fixtures aren't at a wavelength to be considered harmful. Also, an unshielded halide bulb puts out MUCH more UV than a few little LEDs. But with enough low power true UV LEDs,you can cause yourself some trouble.

But to answer your question, there is no point in putting a shielding lens on a true UV LED if you are trying to use it as such. LEDs put out fairly narrow spectra, so blocking the UV with a lens really is just blocking all the light.

What we are actually wanting out of all of this is the deep violet which gives a blacklight effect. Going deeper into the UV wavelength actually does not yield more fluorescence, so there really is no point.

[kien]

Originally Posted by mike31154

I did a little more digging re the UV issue & found this article. They've carried out some measurements on various bulb types, technologies, their UV output & how much UV-A in particular actually makes it through some of the so called glass shields that envelop lamps. UV-B & -C are downright nasty & can really hurt you as well as most any living thing.

http://www.aquarium-design.com/reef/uvlighting.html

That's an interesting article on UV! So in other words. 1. the uv shields on halide bulbs only block out some UV and by some I mean hardly any. 2. UV is harmful to corals.

[Dearth]

I am no expert and have only ever had LED lights I took this picture today of my tank i have had this setup for 5 months and the lights are only at 60% intensity so far I started at 20% and gone up from there. This was a kit from RapidLed and a friend built for me there are 6 blue, 4 white, 1 red and one moonlight.

Sorry my IPhone 4 doesn't do justice but with the exception of one coral all my coral are thriving under this set up with full bloom and great colour. Almost all came from a MH tank and within days were doing great and are all growing at a fast rate. I wouldn't go with any other lighting setup because I am very impressed with how well the coral are thriving under the LED lighting.